Process modelling in laser forming of doubly-curved sheets from cylinder shapes

3D laser forming Laser forming becomes a more practical process in industrial applications depending on the inverse problem for a desired shape, in which the process planning (heating line and heating condition) is one of the most important parameters. The forming is more efficient for the doubly curved plate thermally formed from the rolled cylinder plate than from the flat plate in industry. Therefore, this paper presents a planning strategy for the heating line and the heating condition in laser forming of doubly curved shapes from singly curved shapes. A finite element model accompanied with strain energy optimization is established to develop the saddle sheet to the cylinder shape, which can determine the strain distribution that is required in the thermal forming process. The heating paths on the cylinder surface are automatically generated by the vector transferred from the synthesized strain. The heating condition including laser power and scanning velocity are determined by geometrical difference along the corresponding heating lines between the initial cylinder and target saddle surfaces. The overall methodology is validated by experiments.